Mathematical top



July 24, 1923- v 1,462,870

' J. B. ROGERS MATHEMATICAL TOP Filed Jan. 7, 1922 Patented July 24,1923.

JAMES B. ROGERS, OF CHICAGO, ILLINOIS.

MATHEMATICAL TOP.

Application filed January 7, 1922.

T 0 all whom it may concern:

Be it known that I, JAMES B. Rooms, a

citizen of the United States, residing at Chicago, in the county of Cookand State of Illinois, have invented new and useful Improvements inMathematical Tops, of which the following is a full, clear, concise, andexact description, reference being had to the accompanying drawing,forming a part of this specification.

My invention relates to mathematical tops, such as may be used foreducational or amusement purposes.

One of the objects of my invention is to provide a mathematical topwhich will arouse interest by presenting a new and different problem forsolution each time the top is spun; a further object is to provide novelnumber indicating and novel operation indicating means.

A further object of my invention is to provide a mathematical top whichwill be durable and eflicient in operation, simple in construction andcheap to manufacture.

Further objects will appear from the detailed description to follow andfrom the appended claims.

In the drawings in which an embodiment of my invention is shown Figure 1is a plan view of a mathematical t0 Fig. 2 is a section substantially onthe line 22 of Fig. 1; and

Fig. 3 is a perspective view of the operation indicating ring.

The top comprises a central spindle 10, and a hollow sheet metal bodyportion 11, provided with two concentric ball races 12 and 13, and anoperation indicating ring 1 1, rotatably mounted on the spindle 10, andprovided with a number of retarding wings 15, which meet with airresistance as the top spins, and retard the ring 14, causing relativemovement between the ring 1 1 and the body portion of the top. Balls 16and 17 are provided, one for each ball race, these balls being mountedto travel in their re spective races as the top spins, the inertia ofthe balls and the spinning and wobbling motion of the top causing arelative movement between the balls and the body of the top as the topspins.

The inner ball race 12 is provided with five (5) little pockets ordepressions 18, equally spaced about the ball race, the ball Serial No.527,565.

16 dropping into one of these pocket-s when the top stops spinning.

The upper portion of the body 11 of the top is provided with five (5)small sight openings 19, one located above each of the pockets 18, sothat one can readily see which one of the pockets 18 the ball 16 finallydrops into.

In a similar manner, the outer ball race 13 is provided with ten (10)little pockets or depressions 20, the upper part of the hollow body ofthe top being provided with ten (10) small sight openings 21, onelocated above each of the pockets 20, so that one can readily see intowhich of the pockets 20 the ball 17 finally drops.

The hollow body 11 may be formed of upper and lower sheet metal members22 and 23, the lower member having the ball races and pockets stampedtherein, and the upper member 22 forming a cover portion and having thesight openings 19 and 21 punched therein.

The stampings 22 and 23 forming the body portion of the top may be heldon the spindle 10, which may be of metal, by means of the ears or lugs24, which may be formed on the metal spindle 10, after the sheet metalmembers 22 and 23 are in place, by an op eration well-known in themanufacture of toys and the like.

In order to properly space the sheet metal members 22 and 23, and toinsure proper clearance for the balls 16 and 17, a spacing collar 25 maybe provided, surrounding the spindle 10 and placed between the stampings22 and 23, as shown in Fig. 2. The upper stamping 22 is positionedagainst a shoulder portion 26 on the spindle 10.

The ring 14: is rotatably mounted on the enlarged portion 27 of thespindle, being held in place between the upper stamping 22 and anannular flange 28, formed on the spindle 10. In order to lessen thefriction between the ring 14. and the body of the top, an annular bead29 may be formed on the ring so that there will be line contact betweenthe ring and the upper stamping 22, thereby making it easy for the airresistance acting on the wings 15 to cause retardation of the ring 14and relative m0- tion between the ring and the body portion of the top.

Both sets of sight openings may be numbered, the inner circle of sightopenings benumber of the pocket in which the ball 16 portions -32 and 33in Fig. 1 is such that operation :17 will roll inwardly, and fallpockets provided therefor.

plus, minus, times, divided by and zero, the' latter indicating that nooperation is to be performed.

In using the device, the top is spun in the usualmanner. As the topspins, the balls 16 and 17 move around in the ball races,

and the operation indicating ring 14' is re tarded by the air resistanceand moved relative to the body portion of the top. When "the top finallycomes to rest, the ball 16 will drop into one of the pockets providedfor it, the ball 17 will drop into one of the pockets provided for it,and the operation indicating means Wlll come to rest.

The person spinning the top observes the rests, the number of the pocketin which the ball 17 has come to rest, and observes which one of theoperation indicating signs on the indicating ring has stopped nearest tothe ball in the inner ball race. Asshown in Fig. 1, the ball 16 has cometo rest in the pocket 3, the ball 17 has come to restin the pocket 6,and the indicating ring 14 has stopped with a minus sign nearest theball 16. The problem is, therefore, 6 minus 3.

If the ball 16 should stop in the pocket 4, the ball 17 in the pocket 9,and the operation indicating ring 14 to stop with the multiplicationsign nearest the inner ball race, the problem presented would be 4 times9.

If the operation indicating ring 14 comes to rest with the Zero nearestthe ball in the inner ballrace, no problem is presented, and

one simply spins the top over again.

When the top is spinning, the balls 16 and '17 fly outwardly, the ball17 flying clear out to about the point indicated at 30, and the :ballv16 flying clear out to about the point indicated at 31 in Fig. 2. Thus,the balls 16 :arefree to move without being interfered in their movementby the depressions or pockets 18 and'QO.

The slope of thelo'werstamping 23 at the when the top comes to resttheballs 16 and into the The top may also be used in a somewhat differentmanner as follows: the top is spun in the usual manner, but b'eforeitcomes to tion of the top. hen the top is suddenly arrested, the balls 16and 17 continue to travel around in the ball races, for a number of,revolutions, centrifugal force holdlng .themrinthe outer portion oftheir respective ball races, so that they are not interfered with intheir movement by the pockets 1S and E20. 1

The balls gradually slow up in their movement, however, and each finallyrolls into one of the pockets. The annular bead at the point 31 servesto prevent the ball 16 from escaping outwardly beyond the confines ofthe inner ball race, and the flanges which meet at the point indicatedat 30 serve to prevent the outer ball 17 from escaping beyond theconfines of its circular ball race.

Vhile I have shown but one embodiment of my invention, it is obviousthat it may be embodied in other forms covered and defined by theappended claims.

Having'thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is- 1. A top comprising aspinnable body provided with a circular ball race, and a ball mounted totravel in said race as the top spins and means for preventing the ballfrom escaping outwardly beyond the confines of said circular ball race.

2. A top comprising a spinnable body portion provided with a circularball race concentric with said body, and a ball mounted to travel insaid ball race as the top spins and means for preventing the ball fromes caping outwardly beyond the confines, of said circular ball race.

3. A top comprising a spinnable body provided with a pair of circularball races concentric with respect to said'body portion, 100

a series of pockets, into one of which said ball drops when the topstops spinning and means for preventing the ball from escaping outwardlybeyond the confines of said circular ball race.

5. A top comprising a sp-innable body, .115

comprising upper and lower portions, said lower portion being providedwitha ball race, a ball mounted to travel. in said ball race as the topspins, said upper portion being provided with a series of sightopen- 120 ings through which said ball maybe seen, said ball race beingprovided with ,a series of pockets, one located under each sightopening, whereby said ball will dropinto one ofsaid pockets and bevisible through 2 said sight opening when the topstops spinnmg.

6. A calculating top comprising a spinnable body, two changeable numberindicat ing means, each mounted for independent .130

10 eration indicating means comprising an annular member concentric withsaid body portion, and rotatably mounted thereon, and provided withretarding wings whereby as said top spins the resistance of the air willcause movement of said operation indicating 15 means.

In witness whereof, I have hereunto subscribed my name.

JAMES B. ROGERS.

